A number of indirect markers and indices of liver fibrosis have been used in clinical practice. Noninvasive tests can be distinguished by direct vs. indirect measures of fibrosis and also classified by the modality of the test as serum vs. imaging. Biomarkers of the structural elements of fibrogenesis and the key inflammatory mediators involved in the genesis or degradation of scar tissue are often referred to as direct components. Indirect markers can reflect the accompanying alterations in hepatic function.